How create a map based edge wear shader?
The only way I know to do anything like this is to take the heightmap into the Compositor (I connected it as an emission, aligned the camera and rendered to get it this way - choose whatever method works best for you). The next step is to take the difference between a blurred version of the image and the original. Anywhere with a &quot;sharp cutoff&quot; will be highlighted (assisted by a ColorRamp). It isn't perfect, as you can see from the photos. I picked a &quot;noisy&quot; texture on purpose to how many non-edges I could eliminate, but it's still rather noisy. The success will depend on the &quot;cleanliness&quot; of the original heightmap.
Here is my node setup in the compositor. The original heightmap image is on the left.

Here are just the nodes (for easier viewing). You will have to adjust the ColorRamp to your needs (it can be rather finicky finding the correct range).

From here, it's just a matter of saving your image and using it as a mask for your material. Here's my original material without and with the whites of a Noise Texture added to the &quot;edges&quot; using the mask I made (color channel only).
Without &quot;edge wear&quot; mask:

With &quot;edge wear&quot; mask:

As you can see, it's not perfect. It's still a bit &quot;noisy&quot;, however it is obeying the &quot;rules&quot;, so to speak. The areas that are highlighted are the ones that have the harshest cuttoffs, it's just that I picked a &quot;bumpy&quot; texture to begin with. Hopefully your heightmap will be a bit cleaner (as I said, I picked the noisiest one I could find), and you will have more success.
Here's an example with a &quot;clean&quot; heightmap (keyboard):

Again, here is final material without &quot;edge wear&quot;:

And here it is with the edge wear. Note- I know noise is not a great texture to emulate wear - I just used it as a quick way to get some distortion to the white.